People who use portable devices demand optical devices that have high resolution, are small, and have various photographing functions (an auto-focusing (AF) function, a handshake compensation or optical image stabilization (OIS) function, etc.). Such photographing functions may be realized by directly moving a plurality of lenses that are combined. In the case in which the number of lenses is increased, however, the size of the optical devices may be increased.
The auto-focusing and handshake compensation functions are performed by tilting or moving a lens module including a plurality of lenses, which is fixed to a lens holder in the state in which the optical axes of the lens are aligned, along the optical axis or in the direction perpendicular to the optical axis. An additional lens moving apparatus is used to move the lens module. However, the lens moving apparatus has high power consumption, driving members, such as a magnet and a coil, are required to move the lens module, and available space for moving the lens module is needed in amount corresponding to the range in which the lens module is to be moved. As a result, the thickness of a camera module and an optical device is increased.
Therefore, research has been conducted on a liquid lens configured such that the curvature of the interface between two kinds of liquids is electrically adjusted to perform the auto-focusing and handshake compensation functions.